The answer to the question at the end is clear: she's after (political) power... and president of a sovereign nation is as powerful as you can get.

She won't persue Alaskan secession though, not unless McCain gets thoroughly trounced in the election.. why be president of a small (population) state such as Alaska, when you can be president of the most powerful nation in the world?

The scary thing is that she just might attain it.